D7h trans problem

[muller]

Hello, look i have a d7h and at first it shifts ok but sometimes when you start to work if you are on reverse first gear and and you go to neutral to shift to forward it wont shift you have to return to neutral and then go again to forward and it will shift i checked preassures on the trans pump and it is fine, the strange thing is that when you are pusshing materia it goes fine, it only hapens when you take out the gear.

hope someone can help me it is a d7h 79z0897 sn

 

[tracksfan]

I have a D6H non-diff steer and i was getting bad oil sample readings of high iron. it worked fine except for a problem shifting similar to what you are describing. When changing the oil I found fiber and rubber particles in the suction screens, the trans filter looked pretty clean. All pressure tests were in spec.

Several oil changes and i was still getting high iron readings, it was time to disassemble.. I posted some info and pics of what I found if you want to look. several of the steel plates and friction disks were worn out.

I estimate 7000 hours on my trans?

Also one of the clips on the shift cable end had fallen off where it attaches to the bell crank allowing excessive play when shifting. I found the clip during teardown, luckily it didn't get ground up in the works. replaced it during the assembly.

first, have you adjusted your shift cables/linkages within spec?

Is it diff steer, how many hours, what are the oil sample readings, any debris found in your suction screens, does it run hot, etc?

With more info someone on the forums should be able to help.

I've got mine back together but have not been able to get in the dirt and really test it out. My shift linkage was way out of adjustment and I think that was probaly why it wouldn't shift sometimes, not because of the worn plates/disks.

All for now

 

[muller]

thanks, for the advice, look i allready checked all the suctionscreens and they were all clean, the thing is that when the oil is hot works the same as id when it is cold, also it pucshes fine the dirt.

 

[Per Eriksson]

Check P1 and P2 pressures also while shifting.
The time for pressures to rise and fall should be the same for all speeds and directions, if longer on any gear it could be the seals on that pistion that's worn.

I don't know if your machine has the updated modulating spool in the control valve but it could give symtoms like yours.